Move items equally from each other/centre/angles?
I think Object\Transform\Push/Pull is what you are looking for.
Select all objects in Object Mode and use Object\Transform\Push/Pull from the menu. As the name suggests it will push or pull from the center of all objects.

Based on your comment I assume what you are really looking for is an circular array. Here's a good tutorial for it: https://www.youtube.com/watch?v=bLGYsd4lEjY
Once you set it up you can move your object in edit mode (so the origin stays at the same position) to push/pull the array from the center.